Balast resister & ign. resister are the same thing. Voltage reducer is used to cut the voltage down for 6 volt acess. You must use one for your gas gauge or you won,t get a 2nd chance.
It,s correct the no resister required coil doesn't need a resister or bypass, but personaly I wouldn't use one. They are designed for tractors & low RPM engines. Maybe a 216 might be considerred a low rpm engine but the manufactors never used them on highway vehicles.